Yep, dry it out and the mold should shrivel up and fall off. Or at least be easily scrapped off.
Or use the weed burner suggestion, especially if you don't own one yet....not that any man really needs
an excuse to own one!
18" OTS, 22" OTG, SJ Silver, Cimarron Offset, Coleman Bullet, PBC, UDS, QMaster ATC